text: // Copyright (c) 2018-2020 The Bitcoin Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #ifndef SYSCOIN_UTIL_GOLOMBRICE_H
  #define SYSCOIN_UTIL_GOLOMBRICE_H
  
  #include <streams.h>
  
  #include <cstdint>
  
  template <typename OStream>
  void GolombRiceEncode(BitStreamWriter<OStream>& bitwriter, uint8_t P, uint64_t x)
  {
      // Write quotient as unary-encoded: q 1's followed by one 0.
      uint64_t q = x >> P;
      while (q > 0) {
          int nbits = q <= 64 ? static_cast<int>(q) : 64;
          bitwriter.Write(~0ULL, nbits);
          q -= nbits;
      }
      bitwriter.Write(0, 1);
  
      // Write the remainder in P bits. Since the remainder is just the bottom
      // P bits of x, there is no need to mask first.
      bitwriter.Write(x, P);
  }
  
  template <typename IStream>
  uint64_t GolombRiceDecode(BitStreamReader<IStream>& bitreader, uint8_t P)
  {
      // Read unary-encoded quotient: q 1's followed by one 0.
      uint64_t q = 0;
      while (bitreader.Read(1) == 1) {
          ++q;
      }
  
      uint64_t r = bitreader.Read(P);
  
      return (q << P) + r;
  }
  
  #endif // SYSCOIN_UTIL_GOLOMBRICE_H
  